Furnace for liquid fuel burners



A118. 1933- R. w. BECKETT.

FURNACE FOR LIQUID FUEL BURNERS 2 Sheets-Sheet 1 Filed April 28, 1928 1X1 'ENTOR. M44 4). W

I A TTORNE Y.

Aug. 8, 1933- R. w. BECKETT FURNACE FOR LIQUID FUEL BURNERS "Filed April 28, 1928 2 Sheets-Sheet 2 I N VEN TOR.

A TTORNE Y.

Patented Aug. 1933 PATENT OFFICE 1,921,798 I FURNACE r01: LIQUID FUEL BURNERS Reginald w. Beckett, Detroit, Mich, assignor, by

mesne assignments, to Timken Silent Automatic Company, Detroit, Mich., a Corporation of Michigan Application April 2a, 1928. Serial No. 213,522 6 Claims. (01.158-4) The present invention relates to furnace construction adapted particularly for use with liquid fuel burners.

Among the objects of theinvention is means to properly locate the combustion of the fuel so as to provide for the most absorption of the heat produced thereby.

Another object is means to aid such combustion thereby to enable a more eflicient production of the heat.

Other objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in which:--

Figure 1 shows, partly in section, a steam or hot water furnace including the invention;

Figure 2 is a plan view of a portion of the hearth therefor;

Figure 3 is an end view of one of the hearth elements, and

Figure 4 is a partial top view of the same; Figure 5 is a horizontal section through a portion of a rectangular furnace showing the end tiling; Figure 6 is a section on line 66 of Fig. 5;

Figure '1 is a view similar to Figure 5 showing a smaller furnace;

Figure 8 is a section on line 8-8 of Fig. '7, and Figure 9 is a perspective view of one of the end tiles. 1 In the drawings, a furnace of usual construction is shown at 10 with the water leg at 11, ash pit at 12, and the doors 13. The furnace, however, is shown as modifiedby the removal of the usual grate and the building in of a hearth 15 of suitable material and the installation of a suitable oil burner 16, it being understood that the various controls, fuel tank, etc., are used but not shown. The hearth 15 for the greater portion of its area is formed of suitable flat portions or may be of one annular member extending from the burner 16 to within a few inches of the inner wall of the water leg 11. The extreme edge of the hearth, however, is formed of the elements 100 shown in Figures 2, 3 and 4, filling the gap between the edge of the flat part and the water leg wall, being placed against the latter.

These elements 100 are formed of suitable fire-proof material and either curved or straight to conform to the contour of the water leg wall, rectangular furnaces requiring the use of both forms, curved elements being used in the corners.

The elements 100 whether curved or straight, 55 aonsist of a stepped member comprising a continuous base portion 25, an upright continuous back portion 26, a forwardly projecting guttered step portion 27 forming part of the base 25, and an upper step portion 28 divided by passages 29 into a large number of upstanding ribs 30.

Each rib 30 is further provided on its sides with a series of narrow vertical ribs 31 and its top faced as at 32, which faceting extends over the upper part of the back portion 26 as shown clearly in Figs. 3 and 4.

The gutter 27a is provided to receive any liquid fuel that may collect upon the surface of the tile when the burner is started cold but its chief function is to aid ignition by providing for an oil accumulation at the base of the tile readily ignited by a pilot or other means and permitting rapid propagation of the flame to points distant from the igniting means.

The passages 29 have their bottom walls ribbed also and curved upwardly from near the projection 27 to the top of the element near the back, and are placed close together to form a multiplicity of ribs 31, while the ribs 31 cause the fuel mixture entering such passages to be thoroughly churned and adequately mixed and brought into contact with the multitude of surfaces of the element.

As the element 100 projects upwardly into the path of the projected mixture, the inner face of each rib 30 and also the rear wall of each pocket or passage 29 forms an impact or deflecting surface for the mixture, causing the development of sufiicient pressure to force the gases upwardly. This rush of gases upwardly past the upper surfaces of the element produces above each such surface a relatively lower pressure region, due to an entraining or injector action, which low pressure provides an important effect, namely, it causes eddying of the gases and there by tends to hold down the flaming mixture upon the top of the elements 100 and therefore against the heat absorbing wall of the furnace.

This low pressure is increased by notching the ribs 30 as at 30a to form in effect a groove in which the mixture will be at a relatively lower pressure than elsewhere.

In the operation of the furnace, the elements 100 soon become heated and as the gases and fuel particles are projected horizontally from the rotary member 16, they strike the multisurfaced hot element and also are forced into the passages 29 being violently mixed therein by the ribbed walls and contacted with the hot surfaces, the liquid particles are gasified and caused to mix with the accompanying oxygen. The curved bottom surfaces of the passages preclude the gases being pocketed with consequent eddying and interruption of the smooth flow, which interruption and eddying will cause undue cracking and formation of carbon deposits.

It is probable that the elements 100 perform two functions in this operation, viz., gasifying the liquid fuel and aiding combustion. It is also probable that they act catalytically in the latter function. In any event, the use of such elements with their multitude of small surfaces and projections increases the efliciency of the combustion and aids in maintaining the combustion in close proximity with the base of the heat absorbing surface, the device referred to above as burner 16 being only a mechanical device for projecting towards the surface a mixture of finely divided fuel particles and combustion supporting medium in proper proportions.

The present tile is also adapted for use in furnaces having rectangular fire boxes but in some cases it is preferred to use in addition, tiles 200 such as are shown in Figs. 5 to 9 located at the ends of such fireboxes and especially at that end having the gas outlet to the chimney.

The end tile preferably consists of a rectangular body portion having on one face a plurality of frustro-pyramidal projections 201, each ribbed on its sides and faceted on its top as shown.

These tile are set one end behind the stepped tile 100 with the upper about two thirds projecting above the latter as shown in Figs. 6 and 8. In the case of fire boxes of great length, i. e., those having a length more than about 1.4 times the Width, the end tile are spaced from the end wall or walls of the firebox by such a distance as will bring the long dimension down to approximately the above ratio.

These end tile will be used usually at one end only of the fireboxthe gas outlet end-although they may be used at both ends if desired, and serve the purpose of preventing the combustion taking place at a point spaced above the tile 100 and also interfere with the too easy flow of the gases out of the firebox. Being recessed and having the multi-surfaced projections as in the case of tile 100, they also aid in the mixing of the fuel and air and the combustion control.

Now having described the invention and the preferred form of embodiment thereof, it is to be understood that the said invention is to be limited not to the specific details herein described and illustrated, but only by the scope of the clai which follow.

What I claim is:-

1. In an oil burning furnace, a hearth having an element of refractory material located at its periphery and extending upwardly in the path of the combustible mixture, said element presenting substantially vertical walls to, and having passages therein open to the approaching combustible mixture, said passages having their bottoms curved upwardly.

2. In an oil burning furnace,.a' hearth having an element of refractory'material locatedat its periphery and extending upwardly in the path of the combustible mixture, said element having passages therein open to the approaching combustible mixture, the bottoms of .said passages extending from the front face of said element near the hearth level in a substantially regular curve upwardly to the top face thereof near the rear, the front face of said element presenting a substantially vertical surface.

3. A hearth element for oil burning furnaces consisting of a body of refractory material of L-shaped or stepped cross section, the horizontal member of which is provided with a longitudinal groove in its upper surface and the vertical member of which is provided with a plurality of passages open to that surface adjacent the horizontal member of the body and also open to the upper surface of said vertical member.

4. In an oil burning furnace, a burner spaced from the furnace walls, a hearth surrounding said burner and comprising a substantially horizontal portion having at its edges adjacent the furnace wall a refractory element located in the path of combustible mixture from said burner, said element being provided with a plurality of vertically disposed passages extending through the front face thereof and open throughout their length to the approaching combustible mixture, the bottoms of said passages being above the level of said hearth.

5. A hearth element for oil burning furnaces consisting of a body of refractory material of stepped cross section, the upstanding or riser member of which is provided with a plurality of passages open to that surface adjacent to the horizontal member of said body and also open to the upper face of said upstanding member, said passages stopping short of the bottom of said surface to provide a continuous wall portion below the lower ends of said passages and above said horizontal member.

6. In an oil burning furnace having a combustion chamber, a transversely extending hearth forming the bottom of the combustion chamber, a fuel and air projector for discharging combustible mixture in a transverse path above said hearth, and an intercepting element surrounding said projector and extending above said hearth, said element having a front face disposed in the path of the combustible mixture, said face being provided with a plurality of vertically disposed passages extending through said front face and open throughout their length to the combustible mixture, the bottoms of said passages being above the level of the hearth and above the bottom of said front face, thereby providing a continuous wall portion below the lower ends of said passages.

REGINALD W. BECKETT. 

